Cerevisiae Cells Research Articles

Whole β-glucan particle attenuates AOM/DSS-induced colorectal tumorigenesis in mice via inhibition of intestinal inflammation.

Yeast β-glucan is a polysaccharide purified from the Saccharomyces cerevisiae cell wall, and its multiple biological activities are essential for immune regulation. However, the effect of β-glucan on the intestinal immune response during colitis-associated colorectal cancer (CAC) is unclear. Here, we explore the possible role of β-glucan in the development of CAC. Wild type (WT) mice with CAC induced by azoxmethane (AOM) and dextran sodium sulfate (DSS) had fewer tumors than untreated mice after oral β-glucan because of increased antitumor dendritic cells (DCs) in the tumor microenvironment, resulting in more CD8+ T cells and the production of related cytokines. β-glucan also increased resistance to DSS-induced chronic colitis by reshaping the inflammatory microenvironment. These data suggest that β-glucan improves experimental intestinal inflammation and delays the development of CAC. Therefore, β-glucan is feasible for treating chronic colitis and CAC in clinical practice.

Bioethanol Production from Lignocellulosic Biomass Using Aspergillus niger and Aspergillus flavus Hydrolysis Enzymes through Immobilized S. cerevisiae

Lignocellulose, the main component of a plant cell wall, is a potential renewable bioenergy source. It is composed of cellulose, hemicellulose, and lignin structures. Cellulose is a linear polysaccharide that is hydrolyzed chemically or enzymatically by cellulase. The addition of lignocellulosic biomass, such as wheat bran and coffee pulp, into the fermentation culture, induces the production of cellulases. Cellulose accounts for 20% of the enzyme market worldwide, demonstrating benefits in diverse applications, especially bioethanol and biogas generation. The aim is to evaluate the optimal condition for bioethanol production by previously isolated fungal species from different soil types in the eastern region of the Kingdom of Saudi Arabia. This study attempts to evaluate and optimize the culture conditions of lignocellulosic biomass under SSF using the highest cellulases-producer strains in the region: Aspergillus niger and Aspergillus flavus (GenBank Accession No. MT328516 and MT328429, respectively) to produce raw sugar that consequently is used in the next step of bioethanol production. This process has two parts: (1) hydrolyze lignocellulosic biomass to obtain raw sugar using A. niger and A. flavus that produce cellulase, and (2) produce bioethanol through the conversion of the raw sugar produced from the cellulolysis into ethanol using Saccharomyces cerevisiae. The optimal conditions under SSF were seven days of incubation, 5% glucose as a carbon source, 1% ammonium sulfate as a nitrogen source, and 80% moisture for both isolates. Biochemical characterization showed stability for the immobilized enzyme in all temperature ranges (from 20 °C to 70 °C), while the free enzyme exhibited its maximum at 20 °C of 1.14 IU/mL. CMCase production was the highest at pH 4.0 (1.26 IU/mL) for free enzyme and at pH 5.0 (2.09 IU/mL) for the immobilized form. The CMCase activity increased steadily with an increase in water level and attained a maximum of 80% moisture content. The maximum enzyme activity was with coffee pulp as a substrate of 7.37 IU/mL and 6.38 IU/mL for A. niger and A. flavus after seven days of incubation, respectively. The Carboxymethyl Cellulase (CMCase) activity in immobilized enzymes showed good storage stability under SSF for six weeks, maintaining 90% of its initial activity, while the free enzyme retained only 59% of its original activity. As a carbon source, glucose was the best inducer of CMCase activity with coffee pulp substrate (7.41 IU/mL and 6.33 IU/mL for A. niger and A. flavus, respectively). In both fungal strains, ammonium sulfate caused maximum CMCase activities with coffee pulp as substrate (7.62 IU/mL and 6.47 IU/mL for A. niger and A. flavus, respectively). Immobilized S. cerevisiae showed an increase in ethanol production compared to free cells. In the case of immobilized S. cerevisiae cells, the concentration of ethanol was increased steadily with increasing fermentation time and attained a maximum of 71.39 mg/mL (A. niger) and 11.73 mg/mL (A. flavus) after 72 h of fermentation.

Actualization of productive and reproductive qualities of Hubbard F-15 cross of chickens against the background of the use of immunostimulating preparations PS-7 and Prevention-N-C

Relevance. In modern conditions of industrial poultry farming, technological methods in many respects do not correspond to the biological needs of the bird's body. A high concentration of poultry in limited areas, year-round stay in enclosed spaces in cages leads to negative consequences. Under the influence of unfavorable factors, nonspecific resistance and immunobiological reactivity of the organism decrease. Therefore, at present, the issues of implementing the reproductive qualities and productivity of poultry through the directed impact of biologically active substances are of particular relevance.Methods. The methodology of the work was to study the effectiveness of the use of immunostimulating drugs PS-7 and Prevention-N-C for actualization of the productive and reproductive qualities of hens of the parent flock of the Hubbard F-15 cross. The objects of research were hens of the parent flock of broilers of the French cross Hubbard F-15. In the scientific and economic experiment, according to the principle of analogue groups, three groups of birds were formed with 150 heads each: one control and two experimental groups. Chickens of the 1st experimental group at the age of 21–23 weeks were fed with water three times with an interval of 7 days the biopreparation PS-7 at a dose of 0.1 ml/kg of body weight, chickens of the 2nd experimental group — Prevention-N-C at the same dose and timing.Results. It was found that the use of tested preparations based on the polysaccharide complex of Saccharomyces cerevisiae cells and benzimedazole contributed to an earlier peak of egg production (by 2.0 and 3.0 weeks), increased egg yield on the initial laying hen (by 5.1 and 6.6%) and the average laying hen (by 2.8 and 2.0%), gross egg production (by 1,365 and 1,770 eggs) and livability (by 2.0 and 4.0%). The use of the tested preparations contributed to the improvement of the morphological parameters of eggs and, as a result, the withdrawal of chickens by 0.8 and 2.0%.

Identification of the main proteins secreted byKluyveromyces marxianusand their possible roles in antagonistic activity against fungi

Lytic enzymes secreted by Kluyveromyces marxianus can lyse Saccharomyces cerevisiae cells. Their ability to hydrolyze yeast cell walls can be used in biotechnological applications, such as the production of glucans and protoplasts, as well as a biological control agent against plant pathogenic fungi. Herein, 27 proteins secreted by K. marxianus were identified by mass spectrometry analyses. Importantly, 14 out of the 27 proteins were classified as hydrolases. Indeed, the enzyme extract secreted by K. marxianus caused damage to S. cerevisiae cells and reduced yeast cell viability. Moreover, K marxianus inhibited spore germination and mycelial growth of the phytopathogenic fungus Botrytis cinerea in simultaneous cocultivation assays. We suggest that this inhibition may be partially related to the yeast's ability to secrete lytic enzymes. Consistent with the in vitro antagonistic tests, K. marxianus was able to protect strawberry fruits inoculated with B. cinerea. Therefore, these findings suggest that K. marxianus possesses potential as a biocontrol agent against strawberry gray mold during the postharvest stage and may also have potential against other phytopathogenic fungi by means of its lytic enzymatic arsenal.

Structural characterization of the Aspergillus niger citrate transporter CexA uncovers the role of key residues S75, R192 and Q196

The Aspergillus niger CexA transporter belongs to the DHA1 (Drug-H+ antiporter) family. CexA homologs are exclusively found in eukaryotic genomes, and CexA is the sole citrate exporter to have been functionally characterized in this family so far. In the present work, we expressed CexA in Saccharomyces cerevisiae, demonstrating its ability to bind isocitric acid, and import citrate at pH 5.5 with low affinity. Citrate uptake was independent of the proton motive force and compatible with a facilitated diffusion mechanism. To unravel the structural features of this transporter, we then targeted 21 CexA residues for site-directed mutagenesis. Residues were identified by a combination of amino acid residue conservation among the DHA1 family, 3D structure prediction, and substrate molecular docking analysis. S. cerevisiae cells expressing this library of CexA mutant alleles were evaluated for their capacity to grow on carboxylic acid-containing media and transport of radiolabeled citrate. We also determined protein subcellular localization by GFP tagging, with seven amino acid substitutions affecting CexA protein expression at the plasma membrane. The substitutions P200A, Y307A, S315A, and R461A displayed loss-of-function phenotypes. The majority of the substitutions affected citrate binding and translocation. The S75 residue had no impact on citrate export but affected its import, as the substitution for alanine increased the affinity of the transporter for citrate. Conversely, expression of CexA mutant alleles in the Yarrowia lipolytica cex1Δ strain revealed the involvement of R192 and Q196 residues in citrate export. Globally, we uncovered a set of relevant amino acid residues involved in CexA expression, export capacity and import affinity.

Self-decorating cells via surface-initiated enzymatic controlled radical polymerization.

Through the innovative use of surface-displayed horseradish peroxidase, this work explores the enzymatic catalysis of both bioRAFT polymerization and bioATRP to prompt polymer synthesis on the surface of Saccharomyces cerevisiae cells, with bioATRP outperforming bioRAFT polymerization. The resulting surface modification of living yeast cells with synthetic polymers allows for a significant change in yeast phenotype, including growth profile, aggregation characteristics, and conjugation of non-native enzymes to the clickable polymers on the cell surface, opening new avenues in bioorthogonal cell-surface engineering.

A New, Rapid Method for the Quantification of Dolichyl Phosphates in Cell Cultures Using TMSD Methylation Combined with LC-MS Analysis.

Dolichyl phosphates (DolP) are ubiquitous lipids that are present in almost all eukaryotic membranes. They play a key role in several protein glycosylation pathways and the formation of glycosylphosphatidylinositol anchors. These lipids constitute only ~0.1% of total phospholipids, and their analysis by reverse phase (RP) liquid chromatography-high-resolution mass spectrometry (LC-HRMS) is challenging due to their high lipophilicity (log P > 20), poor ionization efficiency, and relatively low abundance. To overcome these challenges, we have introduced a new approach for DolP analysis by combining trimethylsilyldiazomethane (TMSD)-based phosphate methylation and HRMS analysis. The analytical method was validated for its reproducibility, sensitivity, and accuracy. The established workflow was successfully applied for the simultaneous characterization and quantification of DolP species with different isoprene units in lipid extracts of HeLa and Saccharomyces cerevisiae cells.

Effect of Deletions of the Genes Encoding Pho3p and Bgl2p on Polyphosphate Level, Stress Adaptation, and Attachments of These Proteins to Saccharomyces cerevisiae Cell Wall.

Inorganic polyphosphates (polyP), according to literature data, are involved in the regulatory processes of molecular complex of the Saccharomyces cerevisiae cell wall (CW). The aim of the work was to reveal relationship between polyP, acid phosphatase Pho3p, and the major CW protein, glucanosyltransglycosylase Bgl2p, which is the main glucan-remodelling enzyme with amyloid properties. It has been shown that the yeast cells with deletion of the PHO3 gene contain more high molecular alkali-soluble polyP and are also more resistant to exposure to alkali and manganese ions compared to the wild type strain. This suggests that Pho3p is responsible for hydrolysis of the high molecular polyP on the surface of yeast cells, and these polyP belong to the stress resistance factors. The S. cerevisiae strain with deletion of the BGL2 gene is similar to the Δpho3 strain both in the level of high molecular alkali-soluble polyP and in the increased resistance to alkali and manganese. Comparative analysis of the CW proteins demonstrated correlation between the extractability of the acid phosphatase and Bgl2p, and also revealed a change in the mode of Bgl2p attachment to the CW of the strain lacking Pho3p. It has been suggested that Bgl2p and Pho3p are able to form a metabolon or its parts that connects biogenesis of the main structural polymer of the CW, glucan, and catabolism of an important regulatory polymer, polyphosphates.

Antiproliferative Activity of Philippine Marine Sediment-Derived Actinomycetes

The Philippine archipelago is rich in marine biodiversity and resources that are widely unexplored. Its marine sediments harbor marine microbes that possess secondary metabolites with potent bioactivities. This study aims to determine the antiproliferative activity of the crude extracts of selected Actinomycete isolates (DSD011, DSD017, and DSD042) from Islas de Gigantes, Carles, Iloilo. The antiproliferative screening was done using Saccharomyces cerevisiae as a model organism. Crude extracts of isolates that are active in inhibiting the growth of S. cerevisiae were determined using the broth microdilution method. Afterward, the active extract was tested using antiproliferative and budding yeast assays. With the antiproliferative model, only DSD011 was found to inhibit the growth of S. cerevisiae. The percentage of live and dead cells in DSD011 was comparable to those treated with Triton X (positive control). Further, the budding yeast analysis showed that DSD011 induced G1 cell cycle arrest of nearly 50% of S. cerevisiae cells. Thus, DSD011, a marine sediment-derived Actinomycete, serves as a potential source of naturally occurring bioactive compounds with antiproliferative properties.

Polyherbal decoction modulates redox homeostasis during Malachite green induced metabolic stress in <em>Saccharomyces cerevisiae</em>

Malachite green (MG) is aquatic pollutant that induces oxidative stress when comes in contact with the living organisms. In Saccharomyces cerevisiae, MG produces intracellular reactive oxygen species (ROS) and these ROS disturb redox homeostasis and cellular functions leading to early cell death. Exogenous supply of natural antioxidants containing polyherbal decoction may play a crucial role in re-establishment of redox homeostasis by ensuring the cell survival. Exposure of MG to Saccharomyces cerevisiae resulted in a significant decrease (97.8%) in colony forming units (CFU). An Ayurvedic polyherbal formulation ‘Vayasthapana Rasayana’ (VR) which contains natural antioxidants from plants viz. Terminalia chebula, Clitoria ternatea, Boerhaavia diffusa, Centella asiatica, Phyllanthus emblica, Asparagus racemossus and Tinospora cordifolia at 1.0 mg/mL concentration could arrest the oxidative stress during MG exposure. Levels of ROS elevated up to 67.3% on MG exposure; while VR supplementation reduced it by 54.7%. MG induced cellular apoptosis in 38% and necrosis in 27% cells, while VR augmentation reduced it to 8%. Activities of antioxidant enzymes like catalase, superoxide dismutase and glutathione peroxidase in MG exposed cells were induced by 408, 144 and 140%, respectively, whereas, VR supplementation lowered the expressions to 102, 57 and 111%, respectively. Induction in caspases 3/7 activity was also found to be reduced by 65.39% after VR augmentation. Similarly, VR modulated activities of oxido-reductases like lignin peroxidase, laccase, NADH-DCIP reductase and MG reductase. VR supplementation also maintained the MG utilization potential of S. cerevisiae up to 20th exposure cycle which was otherwise arrested to 8th cycle. The treatment also decreased the ROS accumulation and nuclear damage, restoring the cell viability up to 94% and retained normal growth dynamics. Thus, VR supplementation could significantly decrease oxidative stress, enhance cell viability and ultimately protect the dying S. cerevisiae cells during MG exposure.

Effect of a static magnetic fieldon Saccharomyces cerevisiae growth in wastewater containing phenol and p-chlorophenol

The effect of a static magnetic field (MF) of 7 mT with phenol (P) or p-chlorophenol (p-chP) concentrations of 100 mg∙dm –3 on the proliferation of Saccharomyces cerevisiae yeast was investigated. The abundance of the microorganism was determined under static culture conditions on a YPG medium with or without the addition of P or p-chP and exposed or unexposed to the MF over 48 h of the experiment. A static MF of 7 mT was shown to have a stimulating effect on S. cerevisiae cell proliferation after 24 h. It was proved that P and p-chP were used as an additional carbon source by yeasts. The greatest stimulation of the growth of the studied microorganisms was observed under the simultaneous effect of an MF and in presence of either P or p-chP. It was generally about 2 times higher at the time of the study than in the control. Statistical analysis of the results was carried out using, among other things, analysis of variance (ANOVA). A statistically significant difference in the growth of the tested microorganisms was observed. The study results indicate the possibility of applying an MF of 7 mT to enhance the process of phenol and p-chlorophenol removal from industrial wastewater.

Heterologous expression reveals unique properties of Trk K+ importers from nonconventional biotechnologically relevant yeast species together with their potential to support Saccharomyces cerevisiae growth.

In the model yeast Saccharomyces cerevisiae, Trk1 is the main K+ importer. It is involved in many important physiological processes, such as the maintenance of ion homeostasis, cell volume, intracellular pH, and plasma-membrane potential. The ScTrk1 protein can be of great interest to industry, as it was shown that changes in its activity influence ethanol production and tolerance in S. cerevisiae and also cell performance in the presence of organic acids or high ammonium under low K+ conditions. Nonconventional yeast species are attracting attention due to their unique properties and as a potential source of genes that encode proteins with unusual characteristics. In this work, we aimed to study and compare Trk proteins from Debaryomyces hansenii, Hortaea werneckii, Kluyveromyces marxianus, and Yarrowia lipolytica, four biotechnologically relevant yeasts that tolerate various extreme environments. Heterologous expression in S. cerevisiae cells lacking the endogenous Trk importers revealed differences in the studied Trk proteins' abilities to support the growth of cells under various cultivation conditions such as low K+ or the presence of toxic cations, to reduce plasma-membrane potential or to take up Rb+ . Examination of the potential of Trks to support the stress resistance of S. cerevisiae wild-type strains showed that Y. lipolytica Trk1 is a promising tool for improving cell tolerance to both low K+ and high salt and that the overproduction of S. cerevisiae's own Trk1 was the most efficient at improving the growth of cells in the presence of highly toxic Li+ ions.

Ethanol production by immobilized Saccharomyces cerevisiae cells on 3D spheres designed by different lattice structure types

Natural or synthesized materials can be used for cell immobilization to enhance cell viability and productivity in fermentation processes (batch, fed-batch or continuous fermentations). 3D printing is one of the newest technologies to produce unique immobilization support materials. In this research, the selection strategy of 3D lattice structure type for unique immobilization materials, effect of different lattice structure types on cell immobilization in a shake flask experiments and optimization of ethanol production in a laboratory scale bioreactor with 3D spheres were studied. Firstly, 3D designs were compared to determine the best type of 3D spheres with a higher area:volume ratio for cell immobilization. Then shake flask experiments were performed and showed that W, 20 mm is the best 3D sphere combination for ethanol fermentation. Finally, over 37 g/L ethanol (ethanol yield ranged from 41.91% to 46.36%) was produced at all repeated batch cycles by using 100 g/L initial sugar with at least 82% sugar utilization capacity in a lab-scale bioreactor successfully. All results showed that 3D-printed materials could be used as immobilization agents for microorganisms by selecting the proper geometry, size and printing technology.

Preparation of yeast flakes enriched with iron and vitamin B12 using a pulsed electric field technology

AbstractIn this study pulsed electric field (PEF) was used to increase accumulation of iron and vitamin B12 in Saccharomyces cerevisiae cells, which were then used to produce flakes. The yeast was enriched in two ways: only by adding iron salt (FeCl3·6H2O) and vitamin B12 to the culture medium and by additional application of PEF. Three trials of yeast flakes were prepared: C1 (control, not supplemented), C2—with B12 and iron salt and not treated with PEF, and P—with B12 and iron salt and treated with PEF (for 20 min at 10 μs pulse width, voltage of 1500 V, a number of pulses 1200 and field frequency 1 Hz). The use of PEF resulted in higher iron and vitamin B12 accumulation, respectively, 2.5‐ and 1.4‐fold for the sample P compared to the sample C2. The potential bioavailability of iron from yeast flakes was 10.13% and vitamin B12–4.31%, and the quality of this product was rated good by a sensory panel.

CUP1 Metallothionein from Healthy Saccharomyces cerevisiae Colocalizes to the Cytosol and Mitochondrial Intermembrane Space.

Liquid chromatography, mass spectrometry, and metal analyses of cytosol and mitochondrial filtrates from healthy copper-replete Saccharomyces cerevisiae cells revealed that metallothionein CUP1 was a notable copper-containing species in both compartments, with its abundance dependent upon the level of copper supplementation in the growth media. Electrospray ionization mass spectrometry of cytosol and soluble mitochondrial filtrates displayed a full isotopologue pattern of CUP1 in which the first eight amino acid residues were truncated and eight copper ions were bound. Neither apo-CUP1 nor intermediate copper-bound forms were detected, but chelator treatment could generate apo-CUP1. Mitoplasting revealed that mitochondrial CUP1 was located in the intermembrane space. Fluorescence microscopy demonstrated that 34 kDa CUP1-GFP entered the organelle, discounting the possibility that 7 kDa CUP1 enters folded and metalated through outer membrane pores. How CUP1 enters mitochondria remains unclear, as does its role within the organelle. Although speculative, mitochondrial CUP1 may limit the concentrations of low-molecular-mass copper complexes in the organelle.

Transcriptomic Analysis of Aromatic Amino Acid Biosynthesis Under Nitrogen Starvation in Saccharomyces Cerevisiae

Yeast Saccharomyces cerevisiae has been a preferred organism for scientific research on many sensing and signaling processes. Its ability to adapt to changes in reproductive conditions, especially its fermentative properties have made this yeast species an industrially important species. Because of that S. cerevisiae has been genetically modified to create many kinds of beneficial chemicals from biomass. S. cerevisiae cells have the ability to detect the quality of nitrogen sources in their environment. And It has many regulatory mechanisms to utilize alternative nitrogen sources after the favored sources have been depleted. And proline is the least desired nitrogen source for many laboratory yeast strains. Usage of proline results in the slowest growth rates. The yeast S. cerevisiae can only get cellular nitrogen from tryptophan, tyrosine, or phenylalanine. The major products of this catabolism are tryptophol, phenylethanol, and tyrosol, which are elements of the mixture of alcohols known as fusel oil and this makes yeast S. cerevisiae important also in the production of seconder metabolites. Next Generation Sequencing allows deep analysis of gene expression. The effect of growth in media containing poor nitrogen source, proline, on the aromatic amino acid biosynthetic pathway was observed using NGS technologies in this work. According to the transcriptomic analysis results, we found that 14 genes are responsible for aromatic amino acid biosynthesis and 12 genes (ARO1, ARO2, ARO4, ARO7, ARO8, ARO9, PHA2, TRP1, TRP2, TRP3, TRP4, and TYR1) were down-regulated, while 2 genes (ARO3 and TRP1) were up-regulated. In addition, ARO1, ARO2, ARO4, ARO7, ARO9, PHA2, TRP1, TRP2, TRP3, TRP4, and TYR1 genes have showed 1.5-fold or more expression.

Application of genetically modified microorganisms for potential human amyloids search

Amyloids are fibrous protein structures often found in patients with severe diseases, such as Alzheimers, Parkinsons diseases etc. A number of studies have shown that the production of heterologous amyloidogenic proteins in Saccharomyces cerevisiae strains results in formation of amyloid aggregates with properties similar to those found in mammals.
 Amyloid aggregates formed in yeasts usually do not have their own phenotypic manifestation. To assess amyloidogenic potential of individual proteins a yeast test-system was developed under supervision of Prof. Y.O. Chernoff. The system is based on usage of genetically modified S. cerevisiae cells auxotrophic for certain growth factors, allowing effective phenotypic selection to search for amyloidogenic proteins within proteomes of various organisms [1]. Using this test-system, our laboratory evaluated amyloid potential of a spectrum of human proteins, the amyloidogenicity of which was previously predicted by bioinformatics algorithms. The proteins that have shown amyloidogenic potential in yeast-based model are being currently tested in vitro and in vivo. Some mutant Escherichia coli strains can be applied for studying propensity of heterologous proteins to form amyloids in vitro. Thus, application of genetically modified microorganisms makes it possible to identify new human amyloidogenic proteins and to improve predictive ability of bioinformatics algorithms.
 The research is supported by RSF grant №20-14-00148 and by St. Petersburg State University (project No. 93025998). Authors acknowledge SPbSU Resource Centers Chromas, Molecular and Cell Technologies and Biobank.

Pharmacological effect of T-NilPlus® and Synertox®, commercial anti-mycotoxins, on broiler chickens in Egypt

The present study was carried out to investigate the potential ameliorative effect of two commercial anti-mycotoxins, containing Saccharomyces cerevisiae cell wall as prebiotic (T-Nil Plus®) and Bacillus subtilis as probiotic (Synertox®) on performance and some biochemical parameters of broilers. One hundred and twenty chicks one day old chicks were divided into 3 equal groups. 1st group was served as control, 2nd group was given T-Nil Plus®. The 3rd group was given Synertox®. Chicken’s performance was estimated. Serum samples obtained from each group for biochemical analysis. Tissues samples were collected for histopathological examination. The obtained results revealed that, T-Nil plus® induced a marked reduction in body weight gain and an elevation in Feed consumption, moreover, a marked elevation in, alanine aminotransferase (ALT), creatinine and malondialdehyde (MDA) and a marked reduction in aspartate aminotransferase (AST) was detected. While Synertox® caused a significant decrease in body weight, body weight gain and no change in feed conversion rate (FCR) and a marked elevation in ALT, creatinine and a marked reduction in AST and nitric oxide (NO) and it caused a significant reduction in serum glucose level of the birds. In conclusion, Synertox® induced a powerful effect comparing to T-Nil Plus®, as it induces a good FCR and increases the response of the birds against oxidative stress.

Time-resolved microfluidics unravels individual cellular fates during double-strand break repair

BackgroundDouble-strand break repair (DSBR) is a highly regulated process involving dozens of proteins acting in a defined order to repair a DNA lesion that is fatal for any living cell. Model organisms such as Saccharomyces cerevisiae have been used to study the mechanisms underlying DSBR, including factors influencing its efficiency such as the presence of distinct combinations of microsatellites and endonucleases, mainly by bulk analysis of millions of cells undergoing repair of a broken chromosome. Here, we use a microfluidic device to demonstrate in yeast that DSBR may be studied at a single-cell level in a time-resolved manner, on a large number of independent lineages undergoing repair.ResultsWe used engineered S. cerevisiae cells in which GFP is expressed following the successful repair of a DSB induced by Cas9 or Cpf1 endonucleases, and different genetic backgrounds were screened to detect key events leading to the DSBR efficiency. Per condition, the progenies of 80–150 individual cells were analyzed over 24 h. The observed DSBR dynamics, which revealed heterogeneity of individual cell fates and their contributions to global repair efficacy, was confronted with a coupled differential equation model to obtain repair process rates. Good agreement was found between the mathematical model and experimental results at different scales, and quantitative comparisons of the different experimental conditions with image analysis of cell shape enabled the identification of three types of DSB repair events previously not recognized: high-efficacy error-free, low-efficacy error-free, and low-efficacy error-prone repair.ConclusionsOur analysis paves the way to a significant advance in understanding the complex molecular mechanism of DSB repair, with potential implications beyond yeast cell biology. This multiscale and multidisciplinary approach more generally allows unique insights into the relation between in vivo microscopic processes within each cell and their impact on the population dynamics, which were inaccessible by previous approaches using molecular genetics tools alone.

Novel albendazole-glucan particles for enhancing intestinal absorption and improving hepatic targeting.

Glucan particles (GPs) are derived from the Saccharomyces cerevisiae cell wall. The hollow particles composed of β-1,3-D-glucan have been extensively studied in terms of immune regulation and macrophage-targeted drug delivery. Albendazole (ABZ) is a benzimidazole drug with good anti-parasitic activity and is the drug recommended by the World Health Organization for the first-line treatment of hydatid disease. A dynamic light scatterometer, scanning electron microscope, and transmission electron microscope were used to characterize the ABZ-GPs. High-performance liquid chromatography (HPLC), laser scanning confocal microscope (LSCM) and an in vivo small animal imaging system were used to evaluate theability of ABZ-GPs to be recognized by macrophages, whether ABZ-GPs are more readily absorbed and eliminated in the blood than the original ABZ drug in rats, and the ability of ABZ-GPs to target the mouse liver. The ABZ-GPs were successfully constructed to achieve fluorescence, magnetic resonance imagining, and laser confocal microscopy imaging. The glucan shell effectively protects ABZ from enzymatic degradation and from being pumped out in the gastrointestinal tract. The analysis of ABZ and its major metabolite albendazole sulfoxide in the rat plasma and mouse liver showed that compared to the ABZ suspension group, the degradation of ABZ-GPSs in the blood was low, and the targeting of ABZ-GPSs in the liver was significantly enhanced. In the oral treatment of hepatic hydatid disease, GPs can be used as carriers to achieve the targeted transport of ABZ, which in turn can be used for the targeted therapy of liver echinococcosis. Thus, ABZ-GPs may be a promising form of targeted therapy.